City · North Carolina
ADU rules in Durham
These are the primary sources for accessory dwelling unit regulations in Durham: the city's own zoning code, planning department pages, and permit guides. Start here before talking to anyone: the rules below are what your permit reviewer will apply.
Rules at a glance
The accessory dwelling can be located within the primary structure (attached) or separate (detached) from the primary structure.
UDO Sec. 5.4.2.B.2Attached ADUs (within the primary structure) are expressly allowed; height limits are waived when the ADU is only a conversion of existing space within the primary structure.
UDO Sec. 5.4.2.B.2, B.7.cIf the primary dwelling is single-family, the accessory structure may be a duplex (two ADU units) so long as combined heated area does not exceed 1,200 sq ft.
UDO Sec. 5.4.2.B.4 and B.1.dSec. 5.4.2 contains no owner-occupancy requirement; the full section was read and no provision requires the owner to live in either unit.
UDO Sec. 5.4.2 (no owner-occupancy provision in the section)Stated flatly in the ordinance; civic-use ADUs likewise require no additional parking (B.1.b(4)).
UDO Sec. 5.4.2.B.6Allowed by right on a residential lot developed with one or two primary dwelling units; no special use permit is required (stated expressly for civic-use ADUs, and no discretionary approval is imposed on residential ADUs). Standard building permits still apply.
UDO Sec. 5.4.2.B.1Grepped the full Sec. 5.4 page for rental, lease, and short-term provisions; none apply to accessory dwellings. Durham has not adopted citywide STR-specific zoning rules as of this check.
UDO Sec. 5.4.2The fine print: 8 caveats that can change the picture
- ADUs are prohibited in Special Flood Hazard Areas and Future Conditions Flood Hazard Areas (Sec. 5.4.2.A).
- One ADU per residential lot, allowed on lots developed with one or two primary dwelling units; certain civic uses (e.g. places of worship) may host multiple ADUs under separate standards in Sec. 5.4.2.B.1.b.
- If the primary dwelling is single-family, a detached accessory structure may contain a duplex ADU, capped at 1,200 heated sq ft combined (Sec. 5.4.2.B.1.d).
- RR District size exception: on lots of four acres or larger the ADU may reach 50% of the primary dwelling's heated floor area, but never equal or exceed the primary structure's floor area (Sec. 5.4.2.B.4).
- Density limits do not apply to ADUs (Sec. 5.4.2.B.1.c).
- Travel trailers and RVs may not be used as ADUs in residential districts except during temporary visits of two weeks or less (Sec. 5.4.2.B.5).
- Height: detached ADUs follow accessory-structure height limits; ADU additions follow the primary structure's limits; conversions of existing interior space are exempt (Sec. 5.4.2.B.7).
- Durham is drafting a complete New UDO; the full proposed rewrite entered the adoption process in January 2026, so section numbers and ADU rules may change when it is adopted.
Summarized from Durham's ordinance text, read July 2026; every row links the code section it came from. Rules often vary by zone and lot, so treat this as orientation, not a permit determination, and confirm with the planning department before you commit to a design.
ADU regulations
- udo.durhamnc.govOfficial sourceVerified July 2026https://udo.durhamnc.gov/udo/5_04_Accessory%20Uses%20and%20Structures.htm#5.4.2
- durhamnc.govOfficial sourceVerified July 2026https://www.durhamnc.gov/414/Unified-Development-Ordinance-UDO
- durhamnc.govOfficial sourceVerified July 2026https://www.durhamnc.gov/5527/ADU-Pilot-Program
Spotted something outdated?
Zoning codes change. If a link is dead or Durham has updated its ordinance, report it and we'll verify against the official source.
Report a correctionReady to build?
Planning an ADU in Durham?
Tell us about your project and we'll match you with vetted local designers and builders as we bring them online. No cost, no obligation.